Court: Yep, It’s A Suppressor

SIG’s extend­ed muz­zle brake is, in the eyes of the law, a sup­pres­sor com­po­nent. The U.S. Dis­trict Court of New Hamp­shire upheld the low­er court’s rul­ing in favor of the ATF. “[The] gun SIG Sauer seeks to mar­ket includes a ‘silencer’ under the Nation­al Firearms Act,” reads the rul­ing.

Sig MPX — Court rules muz­zle device is a sup­pres­sor.

Announced at SHOT Show 2013 and put into pro­duc­tion about a year lat­er, SIG’s per­ma­nent­ly-attached muz­zle device has always been a lit­tle con­tro­ver­sial. It was orig­i­nal­ly tout­ed as a brake that could be con­vert­ed to a sup­pres­sor with a thread­ed adapter sleeve. The idea was that SIG could sell the MPX car­bine and cus­tomers could buy an adapter sep­a­rate­ly. This would give shoot­ers the instant grat­i­fi­ca­tion of get­ting the car­bine right away and let them get in the NFA-wait­ing line in their own time.

It was mar­ket­ing genius, and an engi­neer­ing solu­tion to a reg­u­la­to­ry prob­lem. By per­ma­nent­ly attach­ing the muz­zle device to the bar­rel, the MPX brake also brought the over­all bar­rel length to over 16 inch­es long, pre­vent­ing the gun from being NFA-reg­u­lat­ed, too, as a short-bar­reled rifle. The sup­pres­sor adapter was to be the only NFA-reg­u­lat­ed com­po­nent.

Whether the brake legal­ly count­ed as a sup­pres­sor com­po­nent was up for debate imme­di­ate­ly. The ATF quick­ly deter­mined that it was indeed part of a silencer, mak­ing it an NFA-reg­u­lat­ed com­po­nent by itself. SIG filed suit against the ATF’s deter­mi­na­tion in 2014 and, late last year, lost their first law­suit.

The appeals court agreed with the low­er court’s rul­ing and agreed with the ATF. The ATF’s case argued that the device did not func­tion “safe­ly” with­out a sleeve, and that installing a sleeve effec­tive­ly made it a silencer.

The MPX has a hand­guard that extends beyond the first baf­fles of the muz­zle device. This is why the ATF deter­mined that the device was unsafe and required a sleeve; the gasses leav­ing the muz­zle were direct­ed toward the shooter’s hand, putting the user at risk. In a cer­tain light, it may seem like the ATF deter­mined that the device was a sup­pres­sor — after con­vert­ing it to a sup­pres­sor.